Take note of the subscript written for each element in the compound. To find the total number of moles, make sure to multiply the subscript with the number of moles of compound. The answer for each is written below:
a. 3*1 = 3 moles Nitrogen; 3*3 = 9 moles Hydrogen
b. 0.25*2 = 0.5 moles Hydrogen; 0.25*1 = 0.25 moles Oxygen
c. 5*2 = 10 moles Hydrogen; 5*1 =5 moles Sulfur; 5*4 = 20 moles Oxygen
d. 0.75*1 = 0.75 moles Calcium; 0.75*1*2 = 1.5 moles Nitrogen; 0.75*3*2 = 4.5 moles Oxygen
        
             
        
        
        
Considering the ideal gas law, a sample weighing 9.49 g occupies 68.67 L at 353 K and 2.00 atm.
Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P× V = n× R× T
In this case, you know:
- P= 2 atm
- V= ?
- n=  being 2g/mole  the molar mass of H2, that is, the amount of mass that a substance contains in one mole. being 2g/mole  the molar mass of H2, that is, the amount of mass that a substance contains in one mole.
- R= 0.082  
- T= 353 K
Replacing:
2 atm× V = 4.745 moles× 0.082 × 353 K
× 353 K
Solving:
V = (4.745 moles× 0.082 × 353 K)÷ 2 atm
× 353 K)÷ 2 atm
<u><em>V= 68.67 L</em></u>
Finally, a sample weighing 9.49 g occupies 68.67 L at 353 K and 2.00 atm.
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Explanation:
It is known that like dissolves like. Therefore, polar solutes are soluble in polar solvents.
For example, salt is a polar compound and water is a polar solvent. Therefore, salt will dissolve in water.
On the other hand, oil is an inorganic solvent and hence, it is unable to dissolve any polar solute.
Therefore, we can conclude that following is true about the effect of polarity on solubility.
- <em>Polar solutes dissolve better in water than in oil.</em>
- <em>Polar solutes have the greatest solubility in polar solvents.</em>
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<em><u>Hope this helps!</u></em>
<em><u>Please mark brainliest!</u></em>
 
        
             
        
        
        
The given blanks can be filled with attraction and repulsion.  
Gases comprise tiny particles of matter, which are in spontaneous motion. The particles of a gas are colliding continuously with each other and with the container walls. These collisions are considered elastic, that is, no net loss of energy takes place due to collisions. The particles of gases are distinct away from each other by large distances.  
There are no interactive forces, that is, repulsion or attraction among the gas particles. The average kinetic energy of gas particles depends upon the temperature of the gas.  
 
        
             
        
        
        
Hydrogen only has 1 electron so not A.
Barium has 2 valence electrons so answers B!